IRAQ; in war and peace; Hussein's blitzkrieg on Iran: 28 months in a Persian quagmire

Twenty-eight months have passed since Iraq launched its war against Iran. What started out as a ''blitzkrieg'' involving fast-moving armored divisions and infantry has ground into a ''fits and starts'' conflict with Iran militarily holding the upper hand.

The Iranians have regained most of the territory they lost to the Iraqis during the opening stages of the war in autumn 1980. For months, both sides were involved in World War I-style trench warfare. Intermittently, the two bogged-down armies engaged in clashes of heavy armor, leaving the muddy battlefields littered for miles around with burned-out metal hulks. Not since El Alamein in October 1942 had the world experienced such massive tank onslaughts.

But the Iranians went on the offensive early last year. Pushing back the Baghdad forces, they established two major fronts, one in the east, the other in the south, penetrating up to 10 kilometers (6 miles) inside Iraq. The Iraqis themselves admit that roughly 40 square kilometers are at present under Iranian control. Only in Iranian Kurdistan, where Tehran has concentrated one-third of its forces, do Kurdish rebels in uneasy alliance with the Iraqis control sizable portions of mountainous country.

Although the 300,000-strong Iraqi Army has been forced on the defensive, few military observers believe there is any question of an Iranian victory. ''If anything, the performance of Iraqi troops has improved now that they are fighting on home soil,'' said a West European analyst.

The Baghdad high command, which still relies on assistance from an estimated 2,200 Soviet and East European military advisers, has also proved more adept at organizing its defense strategy than trying to hold onto enemy territory. Furthermore, the Iraqi Air Force is still thought capable of controlling the skies.

Various reports from both sides indicate that fighting, at times heavy, is continuing. Although Western journalists have visited both fronts since the Iranian offensives, their movements have been restricted. Official government communiques concerning the war situation are difficult to verify.